LncRNA NEAT1 induces autophagy through the miR-128-3p/ADAM28 axis to suppress apoptosis of nonsmall-cell lung cancer.

Abstract

This study aimed to identify the molecular mechanism underlying NEAT1 regulation of non-small-cell lung cancer (NSCLC) autophagy and apoptosis. The expression levels of NEAT1, miR-128-3p, and ADAM28 in NSCLC tissues and cells were examined using qRT-PCR. The relationships between NEAT1, miR-128-3p, and ADAM28 expression levels and prognosis of NSCLC patients were investigated using the Kaplan-Meier analysis method. The interactions between NEAT1, miR-128-3p, and ADAM28 were confirmed by dual-luciferase reporter assay or FISH assay. Cell proliferation and apoptosis were detected by CCK-8 and flow cytometry assays, respectively. Apoptosis and autophagy-related proteins Bax, cleaved caspase-3, cleaved caspase-9, Bcl-2, LC3, Beclin-1, and p62 were analyzed by western blotting. Finally, an in vivo NSCLC mouse xenograft model was established to confirm the in vitro data. We showed NEAT1 and ADAM28 expression levels were upregulated, while the miR-128-3p level was downregulated in NSCLC tissues and cells. NSCLC patients with high NEAT1 expression levels, low miR-128-3p levels, or high ADAM28 levels had significantly reduced overall survival times. Silencing of NEAT1 inhibited NSCLC cell autophagy and promoted apoptosis by sponging miR-128-3p. MiR-128-3p directly targeted ADAM28 and suppressed ADAM28 expression, which led to deactivation of the JAK2/STAT3 signaling pathway. Furthermore, ADAM28 overexpression attenuated miR-128-3p overexpression-induced apoptosis and autophagy inhibition in NSCLC by increasing the phosphorylation of JAK2 and STAT3. NEAT1 depletion or miR-128-3p overexpression inhibited autophagy and promoted apoptosis in vivo by suppressing ADAM28. In other word, silencing NEAT1 inhibited autophagy and then promoted NSCLC cell apoptosis by deactivating the JAK2/STAT3 signaling pathway through regulation of miR-128-3p/ADAM28 axis.